Programming the correct path does not mean the machine will follow it. High speed and high precision are often contrary terms. By increasing speed precision is reduced but in order to improve productivity speed must be increased. There is always error in the system, the CNC interpolation time, servo system delay and disturbances due to the cutting process, these errors reduce the ability to increase speed and still produce an acceptable part. The common solution to these problems is to program conservatively by slowing down the feeds or by adding an adaptive control system. The CNC and most adaptive control systems interact by feedrate control. This point in the system updates far to slowly to properly control error and can only react after an error is detected - it is too late and too slow to be completely effective. A high gain servo system is much faster but very similar to the CNC - while it reacts quickly to disturbances there must always be an error for a correction.